Collect all ConnectionAttempts from both sockets in TransportConnectJob.

net/socket/socket_test_util.cc

Index: net/socket/socket_test_util.cc
diff --git a/net/socket/socket_test_util.cc b/net/socket/socket_test_util.cc
index cf033c245c3e86c8b5c427c2dc061e49172b7a3a..e0cc3439cb0dc6b72205c6ddb2417afd7582181b 100644
--- a/net/socket/socket_test_util.cc
+++ b/net/socket/socket_test_util.cc
@@ -1006,6 +1006,10 @@ const BoundNetLog& MockClientSocket::NetLog() const {
   return net_log_;
 }
 
+void MockClientSocket::GetConnectionAttempts(ConnectionAttempts* out) const {
+  out->clear();
+}
+
 void MockClientSocket::GetSSLCertRequestInfo(
   SSLCertRequestInfo* cert_request_info) {
 }